With just more than two months left in the 2012 election and the two parties' conventions ramping up, all eyes are on the presidential race.

But there's also a very important and very contentious race for the majority of the Senate in full swing -- the latest development being Rep. Todd Akin's (R-Mo.) implosion in Missouri.

With that in mind, today we are launching our new interactive Senate map, rating each race according to which side is likely to win it.

With Democrats holding a 53-47 majority in the chamber (including independents who caucus with one party or the other), Republicans would need to gain a net of at least three seats -- four if they fail to win the presidency. And both sides have said it's about a 50-50 prospect.

On the map above, we list seven tossups: two Republican-held seats (Massachusetts and Nevada) and five Democratic-held seats (Montana, New Mexico, North Dakota, Virginia and Wisconsin).

Right now we rate Nebraska as a likely Republican pickup and Maine as leaning toward a Democratic pickup. Both feature retiring incumbents in states that lean toward the other party. In Maine, Angus King, the likely winner, is running as an independent but is widely expected to caucus with Democrats if/when he wins.

Beyond those toss ups, Democrats appear to have some hope of picking up seats in Arizona and Indiana, while Republicans have outside shots at stealing seats in two swing states -- Florida and Ohio -- and two other states -- Michigan and Missouri.

In the coming weeks, we will update these ratings as developments warrant and let you know every time a change is made.

Also make sure to check out all the tools available on our ratings page, including breaking states down by any number of factors including unemployment and demographics.